title: Control of an optimal finger exoskeleton based on continuous joint angle estimation from EMG signals.
abstract: Patients suffering from loss of hand functions caused by stroke and other spinal cord injuries have driven a surge in the development of wearable assistive devices in recent years. In this paper, we present a system made up of a low-profile, optimally designed finger exoskeleton continuously controlled by a user's surface electromyographic (sEMG) signals. The mechanical design is based on an optimal four-bar linkage that can model the finger's irregular trajectory due to the finger's varying lengths and changing instantaneous center. The desired joint angle positions are given by the predictive output of an artificial neural network with an EMG-to-Muscle Activation model that parameterizes electromechanical delay (EMD). After confirming good prediction accuracy of multiple finger joint angles we evaluated an index finger exoskeleton by obtaining a subject's EMG signals from the left forearm and using the signal to actuate a finger on the right hand with the exoskeleton. Our results show that our sEMG-based control strategy worked well in controlling the exoskeleton, obtaining the intended positions of the device, and that the subject felt the appropriate motion support from the device.
authors.forename: Jimson
authors.initials: J
authors.lastname: Ngeo
authors.forename: Tomoya
authors.initials: T
authors.lastname: Tamei
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Shibata
authors.forename: M F Felix
authors.initials: MF
authors.lastname: Orlando
authors.forename: Laxmidhar
authors.initials: L
authors.lastname: Behera
authors.forename: Anupam
authors.initials: A
authors.lastname: Saxena
authors.forename: Ashish
authors.initials: A
authors.lastname: Dutta
mesh_terms: D001696:Biomechanical Phenomena; D004576:Electromyography / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D005384:Finger Joint / Q000502:physiology; D005385:Fingers / Q000502:physiology; D005542:Forearm / Q000473:pathology; D006225:Hand / Q000502:physiology*; D006801:Humans; D008962:Models, Theoretical; D009038:Motion; D016571:Neural Networks, Computer; D009989:Orthotic Devices; D015203:Reproducibility of Results; D012371:Robotics / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted